Soundlink micro Low Volume with ALL devices

[Tribeca Volume]

Greetings from Spain,

Two days ago, my one year old Bose Soundlink Micro has started to play everything at low volume. That said:

1. The volume of my 3 devices  (Windows 10 laptop, Android cell and iPhone Cell) connected to the Soundlink are at 100% volume. All worked perfectly until 2 days ago without me intervening to stop doing it.
2. I've reset the speaker.
3. I've updated the firmware.
4. Volume buttons do not work as a result of this issue.
5. I've reset my devices and removed all traces of the Soundlink to start from zero unsuccessful to solve the problem.

What solution can there be for this problem that, I read, is common to multiple users and none of them have been solved in the different topics?

Thank you very much,

Tribeca